moq-net: map MoQ versions to required qmux versions

[kixelated]

Summary

• The MoQ WG decided qmux's draft version is tied to the moq-transport version: moq-transport-18 must ride on qmux-01, moq-transport-14..17 on qmux-00. moq-lite is unconstrained.
• Add the spec mapping to moq-net: QmuxVersion enum, Version::qmux_versions, Version::accepts_qmux, and Versions::qmux_alpns (ordered dedup'd (qmux_version, app_alpn) pairs for building the Sec-WebSocket-Protocol list).
• Existing moq-lite versions (Lite01..Lite04) advertise both qmux-01 and qmux-00 for back-compat. Future moq-lite versions should pin to a single qmux version like moq-transport. The match arms are listed by variant rather than wildcard so any new Lite variant fails to compile until a deliberate choice is made.

Why this lives in moq-net

The composition of (qmux_version, app_alpn) pairs is policy that depends on the moq-transport spec, not on qmux. qmux today (0.0.7) and after moq-dev/web-transport#226 cross-products qmux versions × app protocols internally, which would advertise illegal pairs like qmux-00.moqt-18 or qmux-01.moqt-17. Keeping the mapping here means moq-native can build exactly the right pairs and feed them through whatever opaque-protocol path qmux exposes (or, if needed, prompt a small with_raw_protocols addition upstream).

What's not in this PR

• Wiring through moq-native's websocket client/server and moq-relay's sub-protocol list. That's blocked on the qmux 0.0.8 release that ships PR 226 with an API for explicit pairs.
• Bumping the qmux workspace dep from 0.0.7.

Test plan

• cargo test -p moq-net --lib version:: — 7 new tests pinning the table and per-version mappings, plus the unchanged 327 existing tests, all pass.
• cargo clippy -p moq-net --all-targets -- -D warnings clean.
• cargo fmt -p moq-net -- --check clean.
• cargo build -p moq-native -p moq-relay -p moq-cli — downstream crates still compile against the new surface (it's purely additive).

(Written by Claude)

[coderabbitai]

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Reviewing files that changed from the base of the PR and between d202b31 and 8999f96.

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• rs/moq-net/src/version.rs

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Walkthrough

This PR introduces qmux version support to the MoQ protocol library. A new QmuxVersion enum represents qmux draft versions (00 and 01). Version gains qmux_versions() and accepts_qmux() to enumerate and validate allowed qmux drafts per MoQ version. Versions::qmux_alpns() builds deduplicated (QmuxVersion, app_alpn) advertisement pairs for WebSocket/TLS fronting. Unit tests validate the mappings, acceptance checks, exact ALPN pair tables, and QmuxVersion ALPN strings.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: mapping MoQ versions to required qmux versions, which is the core functionality added in this PR.
Description check	✅ Passed	The description is well-detailed and directly related to the changeset, explaining the spec mapping, implementation rationale, and what's not included in this PR.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch claude/gifted-mcnulty-7eb608

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